The present invention relates to a security wall system in an information processing system and more particularly to a security wall system for protecting user systems against unauthorized accesses via networks and attacks using computer viruses.
With the ever-widening prevalence of the Internet, protection against attacks on corporate systems via the Internet and against reception of mails implanted with viruses has gained an increasing importance. It is also important for low-cost servers to be able to protect systems efficiently against attacks via the Internet without adding special hardware and, as mobile client terminals are coming into wide use in recent years, to provide these terminals with security with a reasonable cost performance.
FIG. 2 illustrates connections of a corporate network using conventional technologies. FIG. 3 illustrates how a mobile terminal is connected to a network. In conventional technologies, when a user system 201 is connected to an external communication network 200 such as the Internet through a LAN, a front end device such as a firewall server 202 is situated in front of the user system 201 (Web server 204, mail server 205, etc.), as shown in FIG. 2, to prevent an inundation of unsolicited packets from the external network 200 (e.g., the Internet), a tampering of files and an infiltration of computer viruses.